<< not sure if garminplugin is needed or just the forerunner tools it pulls in >>
<< but something in the red is required to support udev ownership >>

sudo add-apt-repository ppa:andreas-diesner/garminplugin
sudo apt-get update
sudo apt-get install garminplugin

Plug in the GPS, and select 'garmin' protocol.

lsusb
Bus 003 Device 015: ID 091e:0003 Garmin International GPS (various models)

Allow User to access device
Add user to the plugdev group

sudo vi /etc/udev/rues.d/51-garmin.rules

SYSFS{idVendor}=="091e", SYSFS{idProduct}=="0003", MODE="666", GROUP="plugdev"

sudo udevadm control --reload
Unplug / re-plug device

lsusb
ls -la /dev/bus/usb/XXX


Verify that the group is plugdev

Install GPS Driver

There are two GPS driver methods - a USB one and a Serial 'spoof' one.
It looks like gpsd is the serial version, and is not needed.
gpsbabel is the interface to the GPS, and can do this via direct USB comms.

sudo apt-get install gpsbabel

<-!! note sure about this bit .... -->

sudo apt-get install gpsd gpsd-clients


And Confgure

https://help.ubuntu.com/community/GarminGPSMap76CSx

Test

gpsbabel -T -i garmin -f usb: -o nmea -F -
gpsbabel -w -t -i garmin -f usb: -o gpx -F -